Myasthenia gravis patients are hypersensitive to nondepolarizing relaxants

such as alcuronium

an intermediate-long nondepolarizing agent. This study observed the effects of alcuronium treatment in myasthenia gravis patients as compared with non-MG patients during operation. Ten MG patients （Ossermann class I - IV

scheduled for thymectomy） and 10 non-MG patients （ASA class I-Ⅱ

scheduled for operation） were selected. An induction dose of alcuronium 0. 2 mg/kg and thiopental 4-6 mg/kg was given

followed by intubation and ventilation with 50% nitrous oxide in oxygen and 0.5-1. 5% ethrane. Neuromuscular transmission was monitored using an accelerogragh and degrees of neuromuscular function at different depths were recorded. There were statistically significant differences between the two groups. The effect of alloferin in the MG group was quicker and deeper.This study also found a relation between MG class and the recovery of respiration: Respiratory recovery was quicker in classes I-Ⅱthan in classes Ⅲ-Ⅳ.